Hi,


I have a linux server set up with postfix, which sends emails to our mail servers (MS Exchange).

The linux server itself generates a lot of emails, and I would like to limit the number of mails it can send out pr second so that it doesn't spam our mail servers. Anyone know how I can control the max number of outgoing emails my linux server can send? As of now it's possible for my linux server to cause a denial of service attack on our Exchange server since I have no way of controlling the rate of outgoing messages.

- kenneho

From what I understand, Postfix runs as a set up daemon processes and these are controlled by master.cf. If I am not mistaken, there is a parameter that controls the interval between awakenings of the process. I would look at these settings to see what you can rate limit. You want to be careful though as you will want a sender to be able to connect (pickup daemon) and to have the message go into the queue but not (fully) acted upon so that it sits in an hold queue for a short while. You may still get a burst of emails as it flushes, I am not certain.

This might help http://www.postfix.org/TUNING_README.html#rope